Performance index of steel structure materials

　　1. Strength

　　The strength index of steel is determined by the elastic limit σ e the yield limit σ y. and the tensile limit σ u. The design is based on the yield strength of the steel.

　　A high yield strength reduces the dead weight of the structure, saves steel and reduces costs. The tensile strength σ U is the maximum stress that the steel can withstand before it fails.

　　At this point the structure loses its serviceability due to high plastic deformation.

　　However, the structure is deformed and does not collapse, meeting the requirements of a structure resistant to rare earthquakes

　　2. Plasticity

　　The plasticity of steel is generally defined as the property of having significant plastic deformation without fracture after the stress exceeds the yield point.

　　The main indicators of the ability to measure the plastic deformation of steel are elongation δ and section shrinkage ψ.

　　3.cold bending performance

　　Cold bending performance of steel is a measure of the steel at room temperature when bending plastic deformation crack resistance.

　　Cold bending performance of steel is tested by cold bending test to test the bending deformation performance of steel in the specified bending degree.

　　4、Impact toughness

　　Impact toughness of steel is the ability of steel to absorb mechanical kinetic energy in the fracture process under the impact load.

　　It is a measure of the resistance of steel to impact load cutting of a mechanical property, it may lead to brittle fracture due to low temperature and stress concentration.

　　The general steel impact toughness index is obtained by impact testing of standard specimens.